B, a nucleus. Nuclei are membrane-bound organelles inside eukaryotic organisms. Eukaryotes are protists, fungi, plants, and animal cells. A bacteria is not a eukaryote, it is a prokaryote, so it does not have the membrane-bound structure of the nucleus.
Be careful, though, bacteria still have DNA. It is simply located in the center of the cell and is not encased in a membrane.
Answer;
A.) a law
Explanation;
-A law is a statement based on repeated experimental observations that describes some phenomenon of nature. Proof that something happens and how it happens, but not why it happens.
- A Theory is a well-substantiated explanation acquired through the scientific method and repeatedly tested and confirmed through observation and experimentation.
-A Hypothesis is a proposed explanation for a phenomenon made as a starting point for further investigation.
Answer: hydrogen bonds a protein with no quaternary structure a protein
The nucleus is the center of our cells. it contains our chromosomes and genetic information the produces life.
When stem cells grown on hard, rigid surface, then they became bone cells. Researchers demonstrate in Nature materials that human mesenchymal stem cells grown on a rigid substrate for some time become biased toward differentiating into bone-cell lineage, whereas cell grown on softer surfaces are just likely to eventually follow a bone or fat cell fate.
